Abstract 1419: Characterization of the evolution of immune response in lung squamous carcinogenesis

Abstract

Abstract Molecular profiling of from pre-invasive bronchial lesions, and particularly the evolution of immune response, may identify promising new biomarkers for early detection and targets for chemoprevention/treatment of lung cancer. mRNA expression was analyzed (Agilent microarrays) from fresh frozen human bronchial biopsies (N = 122, 77 patients) at successive morphological stages of lung squamous carcinogenesis. Modules of co-expressed genes were identified among the stage associated genes, selected using a linear mixed-effects model adjusting for smoking status, gender, and history of cancer as fixed effects and patient as a random effect. Cell type specific signatures were applied to the genes co-expressed in these modules in order to identify the immune response signal through the stages of lung carcinogenesis. Genes expression alterations were grouped into 4 successive molecular steps. Based on their behavior across the 4 steps, 8 modules of genes with different patterns were observed: gene modules primarily up-regulated among the early or late steps, up-regulated in a linearly across the 4 steps, as well as down- then up-regulated (biphasic). Genes signing the presence of activating CD8 and CD4 T cells, as well as some memory B cells were progressively and linearly up-regulated from metaplasia through all stages of carcinogenesis. At the later stages, the transition to high-grade dysplasia, the most significant gene expression changes included immune/inflammatory response genes. At this stage a very strong adaptive immune response is noted involving T cells - mainly Th1 and T regulators - and dendritic cells. In addition, immunosuppressive signals, corresponding to negative co-inhibitory molecules, also significantly appears at the high-grade dysplasia stage. The adaptive CD4/CD8 related immune response starts from the earlier stages (metaplasia) of lung carcinogenesis. The significant modification of inflammatory/immune response genes in association with high-grade lesions suggests, at this critical stage of carcinogenesis, a major role of the surrounding microenvironment with an adaptive immune response, driven by Th1 and Treg cells, and but also, before tumor invasion across the basal membrane, a tumor versus host immunosuppressive response. Citation Format: Celine Mascaux, Mihaela Angelova, Jennifer Beane, Kahkeshan Hijazi, Geraldine Antoine, Karen Willard Gallo, Vincent Ninane, Arsène Burny, Jean-Paul Sculier, Avrum Spira, Jérôme Galon. Characterization of the evolution of immune response in lung squamous carcinogenesis. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1419.